| Li Zijian Art Museum is a space structure with truss as the main force system.Its structure and internal force distribution are different from the frame structure.But the existing norms and research results about the study of progressive collapse mainly focus on the conventional frame structure,the research on the spatial structure of trusses and grids is relatively few.In this thesis,the spatial structure of trusses was taken as the main object,and the application of alternative load path method in space structure was summarized and discussed.Taking the steel structure of Li Zijian Art Museum as an engineering example,the progressive collapse analysis was carried out by using SAP2000 finite element software.The mechanism of internal force redistribution of structure was studied,and the analysis results of linear static and nonlinear dynamic were compared.At last,the failure mechanism of the truss structure was researched on.The main content of this thesis include:(1)The application of alternative load path method in the space structure was discussed,and the three methods of linear static method,nonlinear static method and nonlinear dynamic method were explained and contrasted.The different values of GSA2003,DoD2013 and China’s specification for load combinations and component failure criteria in different analysis methods were summarized.(2)The method of judging the key components in the structure were summarized and compared,and the application of the sensitivity analysis method based on the concept judgment in the spatial structure was discussed.With the example of steel truss,the analysis results of different sensitivity response parameters were compared.(3)Taking the steel structure of Li Zijian Art Museum as an engineering example,the structural sensitivity analysis of the whole structure is carried out.The linear static analysis and nonlinear dynamic analysis to simulate the structure failure was carried out,according to the analysis results of the component importance coefficient.The internal force redistribution of the structure and the anti-progressive collapse ability were discussed.The results of the two analytical methods were compared,and some suggestions were put forward on the shortcomings of alternative load path method in Chinese code.(4)Taking the truss structure system as the research object,the pushdown analysis was carried out to study the failure mode and the internal force redistribution mechanism of the truss structure,and the deformation-resistance curve of the truss structure was obtained. |
